Cooling cycle for internal-combustion engines



Sept. 13, 1949. M. F. KNOY COOLING CYCLE FOR INTERNAL-COMBUSTION ENGINES2 Sheets-Sheet 1 Filed Feb. '7, 1944 Tans/5Y5 r 1 THEF/RM Nu I Sept. 13,1949. M. F. KNQY 2,481,520

COOLING CYCLE FOR INTERNAL-COMBUSTION ENGINES Filed Feb. 7, 1944 2Sheets-Sheet 2 INVENTO? Mme/0N E K/vaY :BY Haze/.5 Mew-g Fosm dc Haze/sFOR THE F/RM Arne/4:75

Patented Sept. 13, 1949 UNITED STATES PATENT orrice COOLING CYCLE FORINTERNAL- COMBUSTION ENGINES Marion F. Knoy, Long Beach, Calif.,assignor to Robert T. Collier, Wilmington, Calif.

Application February 7, 1944, Serial No. 521,354

This invention relates to cooling or refrigeration broadly, and moreparticularly to sealed circulating systems for cooling internalcombustion engines or other types of heat generating engines includingturbines.

A principal object is to maintain regulated I cooling in accordance withtemperatures generated in the engine. This object is accomplishedengines and the like through the medium of the cooling-liquid jacketemployed in such engines.

Therefore, stated briefly, one phase of the invention resides inemploying the heat generated in an internal combustion engine by passingrich absorption liquid of the gas-absorption refrigeration type throughthe cooling-liquid jacket of the engine, whereby the heat of the engineserves to liberate the dissolved refrigerant gas contained in theabsorption liquid, thereby to operate the gas absorption refrigerationcycle. By thus evaporating the refrigerant gas from the absorptionliquid, the engine is correspondingly cooled.

For a better understanding of the various phases of this invention, itmay be stated that the conventional gas absorption cycle comprises aheated so-called generator to which is fed a "rich absorption liquid(commonlywater which has been enriched by absorbing therein an operativeamount of a refrigerant gas, commonly ammonia), the refrigerant gas anda small proportion of water vapor being expelled from the liquid by theapplication of heat to the generator; an accumulator or separator intowhich the hot liquid and. gas are conveyed and in which the gasseparates from the liquid; a so-called analyzer into which the separatedgas and usually some water vapor enter and in which they pass throughfresh rich absorption liquid passing to the generator; a rectifierthrough which the gas passes to remove any water vapor remaining; anelevated condenser to receive andliquefy the refrigerant; an elevatedevaporator into which the liquefied refrigerant flows and into which anuncondensable carrier gas. such as hydrogen, enters, and wherein therefrigerant evaporates in the pres- 20 Claims. (Cl. 62-1195) 2 I ence ofthe carrier gas to produce the cooling effect; and an absorber into alower portion of which the descending column of spent refrigerant gasand carrier gas passes to rise countercurrently against descending weakor lean" absorption liquid (i. e., liquid largely denuded of therefrigerant gas) flowing by gravity from the accumulator into the top ofthe absorber, whereby the liquid absorbs the refrigerant gas (with heatevolution) and returns by gravity to the analyzer and thence to thegenerator, the hydrogen leaving the top of the absorber and returning tothe evaporator circuit.

In employing a gas absorption cycle for the cooling of internalcombustion engines, I propose to use the cooling jacket of the engine asa generator and a gas absorption liquid as the cooling liquid. Thus,boiling of-the refrigerant from the absorption liquid in the coolingjacket accomplishes cooling of the engine, without regard to whether ornot the evaporator of the cycle is used to produce refrigeration at adesired point or otherwise.

The gas absorption refrigerating cycle employed for the present purposeof cooling heat generating engines may be conventional. However, thepreferred form of cooling system here used also contains novel features,which include a gas lift, or vapor lift, for elevating the richabsorption liquid to establish a head which is higher than that in theabsorber whereby to augment the feed of the rich absorption liquid tothe cooling jacket of the engine to be cooled. Another feature of theinvention is that, under heavier heat loads developed by the engine, theelevated head of rich absorption liquid will be increased by automatictransfer or shift of a greater pro- I portion of the main body of richabsorption liquid from the absorber, than under light heat loads,thereby insuring circulation of still greater amounts of rich absorptionliquid and liberation of more refrigerant vapors to meet effectively thehigher heat loads. This feature of the invention includes employingapertures or perforations in an upper portion of a standpipe in the gaslift device, whereby liquid may flow from the standpipe through theapertures under light loads, and over the top of the standpipe underheavy load conditions. A further feature of this aspect of the inventionresides in providing for the accumulation of excess liquefiedrefrigerant gas not required to produce cooling in the evaporator orrefrigerator of the cycle, whereby this excess liquid refrigerant, e.g., liquefied ammonia, may be directly returned to the rich absorptionliquid and then passed to the cooling liquid jacket of the engine tospeed up the rate of engine cooling by increasing the rate ofvaporization of the refrigerant. Thus, excess quantities of refrigerantmay pass through the heat absorbing, engine cooling portion of the cycleand through the gas lift portion of the cycle without performing anyrefrigeration in the evaporator. only that portion of the liquidrefrigerent being passed to the evaporator which is necessary for therefrigeration required, a thermostatically regulated valve beingemployed for the purposes of the control.

The invention additionally includes the provision of an absorber havinga number of individual Jets for supplying lean absorption liquid toindividual finned coils or tubes through which the spent gases andvapors rise in the absorber countercurrent to the flow of the leanabsorption liquid, thereby providing a back pressure on the liquid andinsuring equal distribution of the liquid to all coils. Another featureof novelty is found in the use of a helical fln having a metal bond tothe internal pipe of a, heat exchanger between the absorber and theengine for heat exchange between the cold rich absorption liquid and thehot lean absorption liquid returning to the absorber. Another feature ofthe invention resides in providing a by-pass around the condenser sothat the hot gases and vapors separated from the hot liquid leaving theengine will pass directly into the evaporator, thereby converting theevaporator into a heater upon cutting the condenser out of the circuit.Thus, the evaporator may be placed in the body of an automobile or inthe cab of a truck, or at any other desired point of use, and employedfor either cooling or heating, as desired.

Other features of the present invention relate to the absorption liquid,the refrigerant, and the carrier gas. Preferably, a carrier gas isemployed other than hydrogen, which carrier gas will not seep throughiron or steel as does hydrogen. Helium is preferred as such a carriergas because its molecule is sufficiently large to prevent loss byseepage through iron and steel parts, thereby making it possible to useiron and steel in the system. Moreover, helium is light enough so thatit can be employed with ammonia gas as the refrigerant and readilyseparated there from in the system, the molecular weight of hellum being4 and that of ammonia being l1.

A further feature of the invention resides in employing a suitablesolute, such as glycerol, or a monohydric alcohol such as methanol, or awater-soluble salt such as calcium chloride, to reduce vapor tensionofthe water and lower the partial pressure, whereby to increase efficiencyfurther.

Another aspect of the invention is found in employing three or moreliquids having different boiling points, two or more of these liquidsacting as refrigerants, so that, when elevated temperatures, such as areencountered in an internal combustion engine under heavy load, cause onerefrigerant to be largely boiled out of the absorption liquid, theliquid of next higher boiling point comes into play. The last-mentionedliquid may also be a vapor-tension reducing agent, as above indicated.For example, in addition to water as the high boiling point liquid,acetone or methyl alcohol may be employed asthe liquid of intermediateboiling point, ammonia or the like being the primary refrigerant, andhydrogen, or preferably helium, being the carrier gas.

In the accompanying drawings wherein certain Referring more particularlyto Fig. 1 of the drawings, the principal parts of the apparatusillustrated are: a conventional internal combustion engine E having anengine block l0; an accumulator and separator K which receives hot leanabsorption liquid from the engine block l0 and in which the liberatedrefrigerant gases separate; a liquid collector L into which theseparated gases are passed to produce a gas lift effect for establishingan elevated head of rich absorption liquid to feed the engine block; acondenser C in which the gases are condensed to form liquefiedrefrigerant; an evaporator or refrigerator R in which the liquefiedrefrigerant produces a cooling or refrigerating effect; and an absorberA in which refrigerant gases are reabsorbed in the lean absorptionliquid.

The engine E and associated equipment just described are shown aspositioned under a conventional automobile hood II, at the forward endof which is ,a grill l3, and at the other end of which areconventionally located a dashboard H, a cowl 15, a windshield l6, and aninstrument panel H. In addition to the engine block iii, the engine Itis shown as having the usual crank case II and crankshaft IS. The engineblock I0 is provided with a series of conventional vertically disposedliquid passages 20 which constitute a cooling liquid jacket surroundingthe conventional cylinder bores 2| in which reciprocate pistons 22connected in any suitable manner to drive the crankshaft IS. A cylinderhead 23, which may be of conventional construction employed on internalcombustion engines, is secured to the engine block l0 in any suitablemanner and is sealed thereon by means of a conventional gasket 24.

The cylinder head 23 is provided with a liquid chamber 25 whichcommunicates in a conventional manner with the vertical liquid passages2| for the purpose of receiving rising liquid and gases therefrom. I

A suitable cooling liquid, such as is described herein, is supplied tothe passages 20 in the engine block l0 as by means of a short connectingpipe 26 which communicates with one lower corner of the engine block asillustrated. When the engine i0 is in operation, it acts as aheatgenerator which vaporizes the refrigerant constituent of the liquid,for example, ammonia, whereby the engine block III is cooled by reasonof the heat absorption accomplished by the vaporizing step. Theresultant hot liquid and liberated gases rise through the passages 20 inthe engine block II and into the chamber 25 in the head 23, from the topof which they pass by way of a riser or neck 28 into the top of theaccumulator and separator K, in which the hot gases separate from theliquid, some of the water vapor condenses, and the liquid descends toleave a gas space 29 thereabove and to establish a liquid levelapproximately as indicated at 30.

The lean liquid in the accumulator K, largely denuded of gaseousrefrigerant, descends into a horizontal heat exchanger II, through whichit travels to the right as seen in Fig. l, and thence rises through aconduit 33 from which it is in- Jected into a header 34 at the top ofthe absorber A.

The absorber A includes, in addition to the header 34, a series ofhairpin coils 35, whose loops extend transversely, each coil beingvertically disposed and descending step by step from the header which itis jetted through the nozzles 41 into streams of ammonia gas andhydrogen, or am monia gas and helium, being fed into the chamber 35after leaving the evporator or refrigerator R, as presently to bedescribed. By jetting the lean absorption liquid from the nozzles 4|into a series of streams of refrigerant and carrier gas, a high degreeof contact between the rising gases and the jetted lean liquid isproduced so that good absorption of the refrigerant in the liquid isobtained, thereby yielding a rich absorption liquid containingsubstantially all of the refrigerant in solution. A particular advantageof the method of employing each absorber coil individually with weakabsorption liquid is that it insures a more even distribution of theliquid among the various coils than could be secured by gravity flowalone. In a vehicle traversing uneven roads, first one end and then theother end of the liquid supply manifold would be higher, with the resultthat most of the lean liquid would tend to run down in the first coilencountered, thus gorging some coils and starving others under varyingconditions.

Since absorption of the refrigerant gas by the lean absorption liquidpresents an exothermic phenomenon, it is desirable to provide for goodcooling. For this reason each of the coils 35 is well provided with fins42 which assist in carrying heat from the gases and liquids in the coilsto the air streams which are directed over the coils 35 in a controlledmanner.- As shown, fiow of air over the coils 35 is automaticallyregulated by means of a thermostat 44 placed in the body of richabsorption liquid in the receiver 38. Preferably the thermostat 44 islocated in the upper portion of the liquid body, somewhat below theaverage liquid level indicated at 45, rather than in the lower portionthereof, in order that the thermostat 44 may be responsive to the mostrecently produced rich liquid. In the device illustrated, the thermostat44 actuates a bell-crank 46 which controls a link 48, which in turnactuates a second bell-crank 43 that controls a series of louvers 58through the medium of a louver-operating rod connected to the bell-crank48. The louvers 50 are pivoted in a louver housing 52 behind the grilll3 and serve to regulate the air stream passing through the grill l3 andthrough the condenser C (as hereinafter to be described) and over theabsorber coils 35. The air currents passing through the lower louvers 50and over the coils 35 are directed by means of a lower baffle 54 and anupper inclined bafiie 55, so that the air streams move with considerablevelocity over the fins 42 and The body of rich absorption liquidnormally 75 accumulated in the receiver 33 of the absorber A wouldstand, for example, at the level 45. This rich liquid passes from thereceiver 38 through a line 53 which is disposed in heat exchangingrelation with warm lean absorption liquid in the heat exchanger section32, whereby the rich absorption liquid is correspondingly warmed. Thisheat exchange effect may be enhanced by the provision of a helical fin8| secured on the wall of the line by suitable metal bonding, such aswelding or soldering, as indicated at 82, the helix creating turbulenceand the metal bond insuring good heat conduction. The line 50 leads thewarm rich absorption liquid from the heat exchanger 32 into the lowerend of a standpipe 64 centrally located in the liquid collector L andconstituting a portion of a gas lift device to raise rich absorptionliquid above the normal level 45 in the receiver 38 .of the absorber Aand thereby establish a higher liquid level and consequent hydrostatichead in the collector L.

In order to produce the'gas lift effect and maintain the higher liquidlevel, a gas and vapor conducting pipe 85 leads from the top of theaccumulator K through the top of the collector L and down into thestandpipe 64, where it discharges'into the liquid body at a point belowthe liquid level 45 in the receiver 38.

The diameter of the depending pipe 65 compared with the diameter of thestandpipe 64 is such that the quantity of gases being expelled by thegas pressure in the accumulator K from the lower end of the pipe issufficient to produce a gas lift effect in the standpipe 34 whichthereby becomes a gas lift chamber whereby to elevate liquid into theupper end of the standpipe 64, whence it passes into an outer chamber 63of the collector L and tends to establish therein a liquid levelapproximately as indicated by the numeral 58, whereby a head of warmrich absorption liquid is created in the collector L to supply liquid tothe engine block In under the resultant hydrostatic pressure. Therebyrich absorption liquid containing refrigerant gas in solution iscontinuously supplied to the passages 20 in the engine block It) inresponse to heat developed therein.

As shown in Fig. 1, the upper end ofthe standpipe 64 is provided withperforations 69, the purpose of which is to permit liquid which iselevated in the standpipe 54 by gas lift during operation of the engineunder light load to fiow out through the perforations to establish theliquid level 68. However, when the engine is functioning under a heavyload so that a large quantity of liquid is being circulated in thesystem and a large quantity of hot gases is being liberated in'theengine block Hi,- the gas lift in I the collector L increases and thevolume of warm rich liquid coming into the standpipe 64 from thereceiver 38 through the heat exchanger 32 by way of the line 60increases to a point at which all of it cannot escape through theperforations 59 .and the remainder overflows from the top of thestandpipe into the collector L under the increased volume effect andthereby supplies an increased quantity of liquid to the collector L andto the engine block III to satisfy the requirement of the greater heatproduction in the engine block Ill under the conditions of the heavyload.

Thus, the present system establishes two liquid levels 68 and 38 in thecollector Land accumulator K successively higher than the level 45 inthe receiver 38 by reason of the gas lift effect in the standpipe 64 andby reason of the gaslift efiect in the riser 20 leading to the chamber29 of the accumulator K. The gas lift effect in the standpipe 61 has thefurther function of supplying additional preheat to the incoming richabsorption liquid by reason of the hot gases and vapors passing throughthe pipe 65 from the accumulator K. This contact of the hot gases andvapors with the relatively cool rich absorption liquid in the standpipe04 serves also to condense out some of the water vapor that may becarried over with the gas from the accumulator K.

The refrigerant gases and vapors which accumulate in the top of thecollector L rise therefrom through a line I0, whence normally they passto an inclined line II and thence to the condenser C. The line H carriescooling fins I2 which assist in lowering the temperature of the gases inthe line H so that any small amount of water vapor that may be carriedover with the gas from the collector L will be condensed, the incline ofthe line II returning such condensed water back by the line I into thecollector L, and thereby acting to that extent as a rectifier for thegases to remove final traces of water vapor therefrom before they passinto the condenser C.

The condenser C is located forward under the hood I2 of the automobilepreferably approximately in the same position that the upper portion ofa conventional automobile radiator occupies, the form of condenser whichis shown being a series of hairpin coils "provided with cooling fins I6,the coils I extending back and forth across the space under the hood I2behind the louvers 50, in which position the coils I5 are cooled by airentering between the uppermost louvers. To facilitate condensation ofthe refrigerant gases in condenser C, the condenser coils I5 are locatedin an air duct 11 formed by end walls I8 and lower and upper walls I9and 00, respectively. The end walls I0 are shown as having their forwardedges secured at the sides of the grill I3 and as supporting the louverhousing r 52. A baflle 8| at the rear edge of the upper wall 80 extendsupward toward the hood I! for the purpose of directing a portion of theair current over the cooling fins I! on the vapor line II.

Under the pressure and temperature conditions of the system, refrigerantgas, commonly ammonia gas, passing-through the coils I5 of the condenserC is condensed into liquid which flows from the lowermost coil I5through a conduit 84 into a liquid refrigerant accumulating vessel 85,from which the liquefied refrigerant fiows through a conduit 06 to theevaporator R. The amount of refrigerant flowing through the conduit 06is regulated by a valve 01 controlled by a. thermostat 88 mounted on thedashboard I4 adjacent evaporator R. Excess liquefied refrigerantaccumulating in the vessel 05 overflows therefrom through a conduit 80and passes to the rich gas absorption liquid line 60. The liquefiedrefrigerant passed by the valve 81 fiows into the uppermost coil of aseries of coils 90 which constitute the evaporator or refrigerator Rdisposed behind the dashboard Il in the driver's compartment of theautomobile. The evaporation of the liquefied refrigerant in the coils 00produces refrigeration in the coils with consequent cooling of thecompartment. To render the cooling effect more efficient, the coils 90-,which are shown as hairpin coils, may be provided with fins 9| to hastenheat exchange. Evaporation of the liquefied ammonia or other refrigerantintroduced into the uppermost coil 00 from the conduit 00 isaccomplished by the introduction of a hydrogen (or helium) gas streaminto the uppermost coil 00 from a hydrogen line 04 which conductshydrogen gas from the header 34 at the top of the absorber'A by way of ahydrogen storage vessel 05. When the hydrogen stream from the line 84passes into contact with the liquid refrigerant in the uppermost coil90, the liquid refrigerant evaporates by reason of the consequentpartial pressure condition established in this portion of the system.vThe result is refrigeration. From the lowermost coil 90, a mixture ofcold ammonia gas and hydrogen returns by a line 96 to the gas receivingchamber 36 in the intermediate portion of the absorber A, whence thecold ammonia gas or other cold refrigerant gas and hydrogen rise throughthe coils 35 in countercurrent contact with the lean absorption liquidentering the coils 35 from the manifold 40 and noz'zles 4|. In thismannner, the refrigerant gas is reabsorbed to produce fresh richabsorption liquid for repetition of the cycle, the hydrogen beingseparated from the refrigerant and returned to the refrigeration zone.With this'mannner of employing a sealed repeating cycle, no newrefrigerating material is required at any time in the absence of leaksin the system. It will be noted that the header 34, the hydrogen storagevessel 95, and the hydrogen line 04 are shown of relatively largecross-sectional areas with respect to the conduits for handling othergases and vapors, the purpose of these greater cross-sectional areasbeing to reduce the frictional contact of the hydrogen in its passageback to the refrigeration zone in the uppermost coil 00, whereby toproduce relatively rapid hydrogen flow and to establish a draught orwind to insure good evaporation of the liquefied refrigerant andcorrespondingly good refrigeration in the coils 90. I

In accordance with another aspect of this invention, the coils of theevaporator B may be employed as heating coils by employing means adaptedto by-pass the condenser C and cut it out of the system. In the formshown in the drawings, a by-pass conduit I00 is adapted to be connectedwith the uppper end of the vertical gas and vapor line I0 by means of atwo-way rotary valve I02, the valve body having an L- shaped passage I03adapted to connect the line I0 with the line II, as shown in Fi 1, whenthe coils 00 are used for refrigeration purposes, and adapted to berotated about ninety degrees from the position shown so as to connectthe vapor line I0 with the by-pass conduit I00 whereby hot gases andvapors rising through the line 10 from the collector L will enter by theby-pass conduit I00.

The other end 'of the conduit I00 leads into the' end of the liquefiedrefrigerant conduit 00 at a point adjacent the connection of the latterwith the uppermost coil 90 of the evaporator R. The body of the valveI02 is adapted to be rotated from the refrigerating position shown tothe heating position just described by manipulation of a push rod I04connected at one end with an operating arm I05 secured to the valvebody, and having its other end mounted in the instrument panel I1 andprovided with an operating knob I06 convenient to the driver. At thesame time that the valve I02 is rotated to convert the coils 90 intoheating coils, it may be desirable to close the liquefied refrigerantconduit 86, and this may be accomplished by means of a rotary valve I 00located between the condenser C and the inlet of the conduit I00 intothe conduit 00. when the coils 90 are employed as refrigerating coils,the valve I08 is open, but when the coils 90- are to be used as heatingcoils the valve I08 is closed as through the medium of a push cable I09connected at one end to an operating lever H secured to the body of thevalve I08 and having its other end mounted in the instrument panel I!and provided with an operating knob 2 convenient to the driver.

In operating the coils 90 of the evaporator R as heating coils, thevalves l 02 and I08 are moved from the position shown in Fig; 1 so as toclose the valve I00 and to rotate the valve I02 through a quarter turnin order to connect the hot gas and vapor line I0 with the by-passconduit I00 and thereby lead hot gases and vapors directly to the coils90, which thereby act as condenser coils and transmit their heat to warmthe air in the driver's compartment.

During periods when the coils 90 operate as heating coils, the carriergas, such as hydrogen or helium, tends to accumulate in the storage.vessel 05 and the header 34 and line 94 connected therewith.Refrigerant and water which are condensed in the coils 90 leave thelowermost coil and flow by gravity through the return line 96 into thegas receiving chamber 36 of the absorber A, whence the liquefiedportions drop down into the receiver 38 and uncondensed gases risethrough the absorber tubes 35 in contact with descending lean absorptionliquid supplied by the manifold 40. The evaporator R may be restored toits capacity as a refrigerator by returning the valves I02 and I08 tothe positions shown in Fig. 1, thereby connecting the condenser C in thecircuit again so that the ammonia or other refrigerant gas is liquefiedtherein and supplied, together with hydrogen or helium as a carrier gas,into the uppermost coil 90, the by-pass conduit I00 being cut out ofcircuit by the valve I02, as shown.

In addition to statements of operation of various portions of the systemas given in connection with the foregoing description of the apparatus,the following description of the operation of the system as a whole isfurnished.

Rich absorption liquid produced in the absorber tubes 35 of the absorberA collects in the re-. ceiver 38 and passes thence through the heatexchanging line 60 in the heat exchanger 32, where- 'by the richabsorption liquid is warmed by indirect heat exchange with the hot leanabsorption liquid passing from the lower part of the accumulator Kthrough the heat exchanger 32 to the outlet conduit 33. Thisheatexchange is facilitated by the turbulence produced by the helicalfin 6| secured on the line 60 by metal bonding. The warm rich absorptionliquid flowing through the line 50 enters the lower portion of thestandpipe 64, where it is picked up by hot gases and vapors issu ng fromthe lower end of the vapor pipe 65 leading from the top of theaccumulator K and elevated by the gas lift effect of the hot gases intothe upper portion of the standpipe 64, whereby to establish an elevatedliquid head such as represented by the liquid level 68 in the collectorL. Under conditions of light load when the gas l ft efiect is relativelylight, the liquid raised by gas lift will flow out through theperforations 69 in the min: the standpipe G4 to occupy the surroundingannular chamber 66, but under conditions of heavy load, whenlargerproportions of hot gases and vapors are being generated, the gaslift effect will be greater and the perforations 69 may not be able toaccommodate the elevated liquid, with the result that the excess willflow over the top of the standpipe 04, tendgreater quantities of richabsorption liquid to the engine block I0 by way of the feed connection20.

The rich absorption, liquid flowing by gravity from the collector Lthrough the connection enters the vertical passages 20 constituting theliquid cooling jacket in the engine block I0 and absorbs the heatthrough the walls of the engine cylinders 2|, with the result thatammonia gas (or other refrigerant gas) is liberated by the heatgenerated in the engine block I0, thereby effecting cooling of theengine. The resultant liberated ammonia gases and hot liquid rise intothe liquid chamber in the cylinder head 23 and thence pass upward by thegas lift effect of the liberated gas through the neck 20, whence theydischarge into the top of the accumulator K. The liberated refrigerantgases and some water vapor separate from the lean'absorption liquidwhich falls into the chamber 29 to establish the liquid level 30, whichhas a position in the accumulator K still higher than the liquid level'58 in the collector L, which is in turn higher than the liquid level 45in the receiver 38 of the absorber A.

The hot gases and uncondensed water vapor in the top of the accumulatorK pass by way of the vapor conducting pipe 65 down into the standplpe 64to perform the above-described as lift effect for elevating the richabsorptionliquid into the collector L. During the gas lift operation,

.contact of the hot gases and vapors from the pipe 65 with therelatively cool, rich absorption liquid in the standpipe 04 causescondensation of most of the water vapors, but at the same time from theincoming rich absorption liquid. The combined refrigerant gases andremaining water vapor accumulate in the top of the collector L and risefrom the top thereof through the gas and vapor line I0, whence theycontinue through the passage I03 in the rotary valve I02 into the gasand vapor line II which feeds the coils 15 of the condenser C. Any watervapor remaining in the hot refrigerant gas is condensed in the line II,such condensation being aided by the fins I2, and flows by gravity backto the line 10 and collector L due to the inclination of the line 1 I.The waterfree refrigerant gases pass through the coils 15 of thecondenser C and are thereby liquefied, the condensed refrigerant thenflowing from the lowermost coil I5 into the refrigerant storage vesseland thence by way of the conduit 86 to the top coil 90 of the evaporatorR, where it meets the stream of carrier gas, such as hydrogen or helium,being discharged across the liquefied refrigerant by the hydrogen line94 leading from the storage vessel 95 connected'with the header 34 at,

the top of the absorber A.

As the liquefied refrigerant and carrier gas flow countercurrent contactwith descending lean absorption liquid which is Jetted into the upperends of the coils ll by the nozzles ll carried by the manifold 40.

The lean absorption liquid is supplied to the manifold 40 and nozzles llby gravity due to the liquid head established at the level 30 in theaccumulator K. This liquid level 30 is sufficiently higher than themanifold 40 that the resultant hydrostatic head overcomes the backpressure produced by the nozzles ll to insure jetting of the leanabsorption liquid uniformly into the upper ends of the coils 3!. Whilethe lean absorption liquid received in the accumulator K is hot at thetime of delivery from the engine block l0, it is nevertheless cooled inthe heat exchanger II by indirect contact with the cool rich absorptionliquid passing to the standpipe M and the engine block ill, the cooledlean absorption liquid flowing to the absorber A through the conduit 33.

From the foregoing, it is apparent that an automobile engine or otherengine which generates heat may be cooled, and that a driver'scompartment may be cooled or heated, by the employment of a series ofheat exchange steps in a sealed system having a series of heat exchangedevices, typified by the coils 80 of the evaporator R, the coils -15 ofthe condenser C, the coils 35 of the absorber A, the heat exchanger II,the passages 20 in the engine block Ill, and the direct heat exchangebetween rich absorption liquid in the standpipe 64 and hot gasesentering from the vapor pipe 65.

As has been described, the air cooling of the coils 15 in the condenserC and of the absorber coils 35 in the absorber A may be regulated as bymeans of the louvers 50, and these louvers 50 may be adjusted either bythe thermostat 44, or manually, as preferred. Again, the control device44 may be a pressurestat operated by varying pressures in the system, sothat, as pressures increase with temperature rises, the louvers will beopened. It is apparent that the temperature of a condensate will rise aspressure in the system rises. However, since the temperatures within thewhole system are largely self-controlled by vaporization, condensation,and absorption of refrigerant gas, it is not necessary to employ thelouvers iii except when closer control is desired.

When liquefied refrigerant is produced in the condenser C in quantity inexcess of requirements of the evaporator R, such excess quantity willaccumulate in the refrigerant storage vessel 85, and if it builds upsubstantially it will overflow through the line 89 and pass directlyinto the rich absorption liquid, as by flowing into the rich absorptionliquid line 60 as shown.

This situation may arise under heavy heat load conditions whereunusually large proportions of rich absorption liquid are shifted fromthe receiver 38 in the absorber A to raise the liquid head in thechamber 66 in the upper portion. of the collector L. As has beendescriber, this shift takes place when high heat load causesvaporization of increased amounts of refrigerant gas which separate inthe accumulator K and pass through the ipe 85 to produce more active gaslift and elevate increased amounts of rich liquid into the chamber 68.

The greater volumes of refrigerant gas generated are required to becondensed in the condenser C with a resultant yield of liquefiedrefrigerant greater than the normal requirements of the evaporator R.Since the thermostatically controlled valve 81 passes only enoughliquefied 12 refrigerant to effect desired cooling by the evaporator R,the remainder of the liquid refrigerant accumulates as an excess in thevessel I, which excess is returned by overflow to the rich absorptionliquid, as above stated. Since the refrigerant content of the richabsorption liquid is 7 thereby increased, a correspondingly greatercooling efiect is produced in the engine block II by a given volume ofabsorption liquid, due to greater heat absorption upon vaporization.Also, a correspondingly greater gas lift effect is produced in thestand-pipe 64 and collector L by the greater volume of gases generated.The result of this phase of the operation is the by-passing andrecycling of substantial proportions of ammonia for engine cooling andgas lift alone without per- {qorming any refrigerating effect in theevaporator From the foregoing. it will be seen that circulation of theabsorption liquid and vaporization of the refrigerant therefrom are at arate proportionate in general to the heat generated by the engine, thesystem responding to increased heat generation by increased vaporizationof refrigerant and increased circulation. Therefore, as heat generationincreases, pressure in the system increases by reason of the greatervaporization, and at the same time the temperature of condensation ofthe refrigerant rises somewhat and the amount of absorption ofrefrigerant in the liquid increases somewhat for a given temperature.However, this rise of a few degrees in temperature is not of suihcientmagnitude to be objectionable.

As previously indicated, a wider range of operating temperatures in theengine block it may be cared for by employing another refrigerant havinga boiling point intermediate that of water and the refrigerant gas.Thus, an appreciable proportion of the water, for example, 10% to 30%,may be replaced by methyl alcohol or acetone. Therefore, whenevaporation of the ammonia from the water does not satisfactorily carefor the cooling of the engine, the more elevated temperaturesencountered will cause the methyl alcohol or the acetone to beevaporated at least in part,

whereby to effect further cooling. Evaporative efficiency of the gasabsorption liquid may be improved by including a solute suitable toreduce vapor pressure and lower the partial pressure. The solute may bea liquid, such as glycerol, or a monohydric alcohol like methanol, or itmay be a water-soluble salt, such ascalcium chloride. when using asubstance such as methyl alcohol, both the functions are performed ofreducing vapor pressure and supplying another evaporative refrigerant ofintermediate boiling point.

As has also been previously indicated, the employment of hydrogen as acarrier gas in iron and-steel parts is ordinarily objectionable becauseof the hydrogen loss by seepage through the pores of the metal. Since itis desirable to employ claims iron or steel in connection with at leastsome of the parts of the system, it is desired to employ a satisfactorysubstitute for hydrogen, helium being preferred. Due to its largermolecule, the

I claim as my invention:

1. In an engine cooling structure, the combination of: an internalcombustion engine having cylinders and a liquid passage in heat transferelation with the cylinders; and a gas absorption system connected tosaid passage in sealed relation, said system and said passage containinga circulatory gas absorption liquid and gas, said passage and saidengine operatin as a generator for said system to liberate gas andcirculate said liquid from said passage to said system and back to saidpassage in response to heat developed by operation of the engine, saidsystem comprising means to condense the liberated gas, means to cool theliquid from which gas has been liberated, and means to feed condensedgas directly into the cooled liquid.

2. In combinationza heat generating power plant having a passage forcirculation of a gas absorption liquid therethrough to cool said plant;and a gas absorption cooling system connected with said passage insealed relation to receive gas absorption liquid from said passage andreturn gas absorption liquid to said passage, heat generated by saidpower plant operating to distill refrigerant gas from said gasabsorption liquid. said gas absorption cooling system including acondenser adapted to receive liberated refrigerant gas and liquefy thesame, a cooler to receive lean absorption liquid, means to conductliquefied refrigerant directly into the cooled absorption liquid forreabsorption of the refrigerant in the liquid, and means to returnresultant rich absorption liquid to said passage in said power plant.

3. In combination: a heat generating power plant which developsfluctuating heat loads between low heat loads requiring minimum coolingand heavy heat loads requiring cooling in excess of normal; a coolingjacket for said power plant adapted to receive gas absorption liquidcontaining absorbed refrigerant gas; an accumulator connected with saidjacket and adapted to receive fluctuating quantities of hot liquid andliberated refrigerant. gas from said jacket at an elevated level toestablish an elevated lean liquid head; an absorber adapted to receivelean liquid from said accumulator by gravity flow; means to conduct leanliquid from said accumulator to sad absorber; a condenser adapted toreceive refrigerant gas from said accumulator and condense the same; anevaporator connected with saidcondenser and adapted to receive condensedrefrigerant from said condenser; means to return refrigerant gas fromsaid evaporator to said absorber in contact with lean absorption liquidfor reabsorption of the refrigerant gas thereby; and collector meansconnected to said absorber and providing a storage zone for a variablehead of absorption liquid varying as said heat load varies to store andto feed enriched absorption liquid to said cooling jacket.

4. A combination according to claim 3 wherein said collector meansproviding for said variable head includes: a gas lift chamber connectedto receive rich absorption liquid from said absorber; a gas line leadingfrom the top of said accumulator into the bottom of said gas liftchamber whereby rich absorption liquid is elevated in said gas liftchamber by hot gases from said accumulator; a collector arranged toreceive the rich absorption liquid elevated in said gas lift chamber toestablish a hydraulic head in saidcollector; and means to conductabsorption liquid from said collector to said cooling jacket.

5. In combination in a sealed system: a heat generatingpower planthaving a passage adap to receive a circulating gas absorption coolingliquid to cool said plant; a compartment to be cooled; a gas absorptionsystem connected with said passage, said system and said passagecontaining a circulatory gas absorption cooling liquid containingrefrigerant gas which is ex lled in said passage by heat generated insaid power plant, said gas absorption system including a condenseradapted to receive liberated gas and liquefy the same, an evaporatorlocated in said compartment and adapted to receive liquefiedrefrigerant, and an absorber connected with said evaporator and withsaid passage and adapted to receive refrigerant gas from said evaporatorand absorption liquid from said passage for reabsorption of therefrigerant gas in said liquid; means to direct cooling air currentsover said condenser and over said absorber; and adjustable means toregulate passage of said cooling air currents.

6. In combination: a heat generating power plant having cooling meansadapted to receive a gas absorption cooling liquid to cool the powerplant by vaporization of an absorbable refrigerant in said liquid; aheat exchange device to receive refrigerant expelled from said liquid; acondenser to receive and condense refrigerant gas expelled from saidliquid; absorption means connected with said heat exchange device toreceive refrigerant gas from said heat exchange device: means to conductabsorption liquid from said cooling means to said absorption means forabsorption of refrigerant gas in the liquid to enrich said liquid;selectively operable valve means to pass condensed refrigerant from saidcondenser selectively to said rich liquid and said heat exchange device;and means to return rich absorption liquid to said cooling means, saidcooling means, said heat exchange means, and said absorption means beingconnected together in sealed relation to retain all the constituents ofthe gas absorption liquid.

7. In combination in a sealed system containing a circulatory coolinabsorption liquid containing absorbed refrigerant gas: a power planthaving heat generating means and a passage in heat transfer relationwith said heat generating means for receiving absorption liquid; aconnection to supply liquid to said pasage; an accumulator connectedwith said passage to receive hot absorption liquid therefrom at anelevated level; means'to receive and cool absorption liquid from saidaccumulator; a receiver for cooled absorption liquid; a gas lift deviceconnected to receive cooled absorption liquid from said receiver; meansconnected to receive liberated hot refrigerant gases from said passageand conduct them to said gas lift device to elevate absorption'llqudtherein; a. collector to receive elevated liquid from the gas liftdevice; meansto conduct the elevated liquid from the collector to theconnec ion'suir plying said passage; means connected to receive andcondense refrigerant gas generated by said power plant; and means toreturn condensed refrigerant directly to said cooled absorption liquid.

8. In combination in a sealed system: an internal combustion engine tobe cooled; a compartment to be cooled; an evaporator in saidcompartment; a cooling jacket connected with said internal combustionengine and having'passages to receive absorption liquid containingabsorbed refrigerant gas which is liberated by the heat of said engine;means to receive hot liquid and 7 gases from said jacket passages; meansconto liquefied form; valve controlled means adapted to supply a portionof said liquefied gases to said evaporator; an absorber adaptedto-receive absorption liquid from said jacket passages and to receiverefrigerant gases from said evaporator for reabsorption of refrigerantgases in said liquid; and means connected with said condensing meansadapted to conduct excess liquefied refrigerant gases directly toabsorption liquid conducted to said absorber.

9. A combination as in claim 8 including additional valve controlledmeans for diverting said hot gases from said condensing means to saidevaporator.

10. A combination according to claim 8 including'thermostaticallycontrolled valve means in said means for conducting liquefiedrefrigerant to said evaporator.

11. A method for cooling a heat generating engine having a passagetherein adapted to receive a cooling liquid, said engine developingfluctuating heat loads between low heat loads requiring minimum coolingand heavy heat loads requiring cooling in excess of normal, comprising:circulating during engine operation a rich gas absorption liquidcontaining absorbed refrigerant gas through said passage and through agas absorption system connected in sealed relation with said passage,said gas being liberated by position higher than normal in response toincreased heat load in the engine and thereby establishing a relativelyhigh hydrostatic head; and Y feeding said liquid under said highhydrostatic head to said passage.

12. A method for cooling a -heat generating device having a coolingliquid passage, comprising: circulating through said passage a coolingliquid containing absorbed refrigerant gas which is liberated by heatgenerated by the device: separating liberated hot refrigerant gas fromthe hot liquid; condensing said refrigerant gas; cooling the separatedliquid; commingling the condensed refrigerant with the cooled liquid;and returning the resultant rich liquid to said passage.

13. A method of operating a cooling system having a variably heatedliquid receiving passage and a gas absorption system having liquidpassages connected in sealed relation with said heated liquid receivinpassage, said heated liquid receiving passage developing fluctuatingheat loads between low heat loads requiring minimum cooling and heavyheat loads requiring cooling in excess of normal, comprising: variablycirculating a rich gas absorption liquid containing absorbed refrigerantgas through said passages as the -heat load of said heated liquidvaries, said refrigerant gas being liberated by heat applied to saidheated passage; separating liberated gas from heated ,liquid to yieldlean absorption liquid; cooling said separated refrigerant gas and saidlean liquid; reabsorbing cooled refrigerant gas in the lean liquid toyield rich absorption liquid; establishing a storage body of richabsorption liquid under conditions of light heat load; transferring asubstantial proportion of said storage body of liquid to an elevatedposition higher than'normal under influence of heavy heat load toestablish a high hydrostatic head; and supplying said elevated liquidunder said high hydrostatic head to said heated passage.

14. A method asin claim 13 wherein said reirigerant gas is condensed andcondensed gas is introduced directly into the absorption liquid.

5. A method according to claim 13, wherein liberated gas separated fromthe lean liquid is employed to raise rich liquid by gas lift to saidelevated position.

16. In combination: a heat generating-power plant having a pasage forcirculation of a gas absorption liquid therethrough to cool said plant;

15 a gas absorptioncoolin system connected with said passage in sealedrelation to receive gas absorption liquid from said passage and returngas absorption liquid to said passage, heat gener-, ated by said powerplant operating to distill refrigerant gas from said gas absorptionliquid, said gas absorption cooling system including a condenser adaptedto receive liberated refrigerant gas and liquefy the same,a cooler toreceive lean absorption liquid, an evaporator to receive lique- 5 fledrefrigerant from said condenser, means adapted to commingle vaporizedrefrigerant with the lean absorption liquid for reabsorption of therefrigerant in the liquid, and means to return resultant rich absorptionliquid to said passage in said power plant; means to pass cooling aircurrents across said condenser and cooler; and adjustable means toregulate said air currents.

17. The combination of: an internal combustion engine to be cooledhaving a cooling jacket for a circulating refrigerant gas absorptionliquid to remove substantially all excess heat generated by the engine,said engine developing fluctua ing heat loads between low heat loadsrequiring minimum cooling and heavy heat loads requiring cooling inexcess of normal and beyond the normal capacity of the gas absorptionliquid; and a gas absorption system including said jacket, anaccumulator connected to said jacket to receive fluctuating quantitiesof hot liquid and liberated 46 refrigerant gas from said jacket, acondenser connected to said accumulator to cool and liquefy saidrefrigerant gas, means to remove said hot liquid from the accumulatorand cool it, means to return said refrigerant gas to the cooled liquid50 to enrich the latter, collector means connected to said cooling meansand providing a storage zone to receive variable heads of enrichedliquid as said heat loads vary and to establish a high hydrostatic headthereof upon increased heat load, and means 65 connecting said collectormeans to said jacket.

18. The combination of: an internal combustion engine to be cooledhaving a cooling jacket for' a circulating refrigerant gas absorptionliquid to remove substantially all excess heat generated by the engine,said engine developing fluctuating heat loads between low heat loadsrequiring minimum cooling and heavy heat loads requiring cooling inexcess of normal; and a gas absorption system including said jacket, anaccumulator connected to said jacket to receive fluctuating quantitiesof hot liquid and liberated refrigerant gas from said jacket, acondenser connected to said accumulator to cool and liquefy saidrefrigerant gas, means to remove said hot liquid from the accumulatorand cool it, means to return said refrigerant gas to the cooled liquidto enrich the latter, collector means connected to said cooling means toreceive enriched liquid, and means connecting said collector means tosaid jacket. 7 5 19. A method for cooling a heat generating power plantof variable heat loads and havinga cooling passage, comprising:circulating through a circuit including said passage a solutioncontaining a high-boiling liquid, 9. low-boiling refrigerant constituentabsorbed in said liquid, and a refrigerant constituent of intermediateboiling point; under normal or low heat load conditions evaporating saidlow-boiling constituent from said solution, conducting the vapors ofsaid lowboiling constituent in a stream through a firs; branch of saidcircuit which includes said passage. condensing the vapors of saidstream in said first branch, conducting the residue of said solution ina stream through a second branch of said circuit, joining said streams,and conducting the resultant composite stream to said passage; and underhigh heat load conditions evaporating from said solution bothrefrigerant constituents and conducting the same in a stream throughsaid first branch of said circuit, condensing the vapor", of the lastmentioned stream insaid first branch, conducting the residue of saidsolution from evaporation of both refrigerant constituents in a streamthrough said second branch, joining the last mentioned residue streamand the last mentioned condensed vapor stream, and conducting suchcomposite stream to said passage.

20. A method for cooling a heat generating power plant of variable heatloads and having a cooling passage, comprising: circulating through acircuit including said passage a solution containing a high-boilingliquid, a low-boiling refrigerant constituent absorbed in said liquid,and a refrigerant constituent of intermediate boiling point; undernormal or low heat load utilizing the heat absorbed in said passage fordriving 011 a vapor stream consisting predominately of said low-boilingconstituent from said solution, conducting the stream of vapors of saidlow-boiling 18 constituent through a first branch of said circuit whichincludes said passage, condensing the vapors of said stream id firstbranch, conducting the residue of d solution in a stream through asecond branch of said circuit, joining said streams, and conducting theresultant composite stream to said passage; and under high heat loadutilizing the heat absorbedin said passage for driving from saidsolution a vapor stream consisting predominately of both refrigerantconstituents and conducting the same in a stream through said firstbranch of said circuit, condensing the vapors of the last mentionedstream in said first branch, conducting the residue of said solutionfrom evaporation of both refrigerant constituents in a stream throughsaid second branch, Joining the last mentioned residue stream and thelast mentioned condensed vapor stream, and conducting such compositestream to said assage.

MARION F. KNOY.

REFERENCES CITED The following references are of record in thefile ofthis patent:

UNITED STATES PATENTS Number Name Date 1,897,223 Altenkirch Feb. 14,1933 1,955,345 Sarnmark Apr. 17, 1934 1,960,821 Maiuri et al. May 29,1934 2,009,067 Mulholland July 23, 1935 2,080,195 Bergholm May 11, 19372,134,188 Haywood Oct. 25,1938

FOREIGN PATENTS Number Country Date 676,408 France Feb. 22, 1930 693,689France Sept. 1, 1930 Certificate of Correction 7 Patent No. 2,481,520September 13, 1949 MARION F. KNOY It is hereby certified that errorsappear in the printed specification of the above numbered patentrequiring correction as follows:

Column 5, line 22, for e orator read evaporator; column 10, line 43,after the word time insert liberates itimwl quantities of refrigerantgas; column 11, hne 63, for describer reed described;

and that the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the casein the PatentOfiice.

Signed and sealed this 24th day of January, A. D. 1950.

THOMAS F. MURPHY,

Aul'etani aonnm'eaioner of Patenta.

